package com.neusoft.bd.myflink.step02;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;

import java.util.Objects;

public class StreamWordCount {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        DataStreamSource<String> lineStream = env.socketTextStream("localhost", 9999);
        // 3. 转换、分组、求和，得到统计结果
        SingleOutputStreamOperator<Tuple2<String, Long>> sum =
                lineStream
                        .flatMap(
                                new FlatMapFunction<String, Tuple2<String, Long>>() {
                                    @Override
                                    public void flatMap(String line, Collector<Tuple2<String, Long>> out)
                                            throws Exception {
                                        String[] words = line.split(" ");
                                        for (String word : words) {
                                            if (!Objects.isNull(word) && !word.trim().isEmpty())
                                                out.collect(Tuple2.of(word, 1L));
                                        }
                                    }
                                })
                        .keyBy(data -> data.f0)
                        .sum(1);
        // 4. 打印
        sum.print();
        // 5. 执行
        env.execute();
    }
}
